Sewing machine drive means



July L 194% R; K. Hol-:MANN ETAL. 2,247,381

SEWING MACHINE DRIVE MEANS Original Filed Dec. 29, 1959 section;

Patented July 1, 1941 SEWING MACHINE DRIVE MEANS Richard K. Hohmann, Jamaica, and Frederick Osann, White Plains, N. Y., assig'nors to Sears, Roebuck and Co., Chicago, Ill., a corporation of NewYork.

Original application December 29, 1939, Serial No. 311,486. Divided and this application August 3, 1940, Serial No. 351,013

4 Claims.

In our prior application, Serial No. 311,486-, filed December 29, 1939, of which this application is a division, we have disclosed a simple and effective sewing machine ydevised by us especially for interchangeable use as a darning machine and for ordinary sewing operations.

That machine is readily convertible from one tothe other of two conditions, in one of which it is adapted for plain sewing and includes a flat work bed, which may be generally similar in form and disposition to the conventional work bed of a plain sewing machine, and in the other of which it is adapted for darning and is adapted to support stockings, or other Work to be darned, on a cylinder arm generally like, though preferably somewhat smaller in cross section than, the work supporting cylinder arms of ordinary darning machines. In its preferred form, the machine is adapted, however, for either plain sewing or darning operations, on flat bed and cylinder arm supported work.I Y

The general object of the invention claimed herein is to provide an improved pulley and belt drive connection between a driving pulley mounted on the needle bar shaft and a driving electric motor located in the base of the sewing machine, and including novel provisions by which the portion of the belt above the base of the machine is normally enclosed within the standard and adjacent arm portion of the machine, but mayv be made readily accessible for belt removal. and replacement operations.

The various features of novelty which characterize our novel work feed mechanism are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specic objects attained with its use, reference should be had to the accompanying drawing and descriptive matter inwhich we have illustrated and described a preferred form ofembodiment of the present invention.

Of the drawing: Fig. 1 is an elevation, partly in section, of a sewing machine constituting a preferred embodiment of the present invention; A

Fig-2 is an enlarged reproduction of a portion of Fig. 1, showing parts in different relative positions;

Fig. 3 is a section on the line 3 3 of Fig. 1 with parts broken away and removed;

Fig. 4. is a perspective view showing parts of the cylinder arm and flat work bed of Fig. 1 in 5 is a perspective view illustrating details of the main pulley mounting;

Fig. 6 is a small scale elevation of a removable cover plate at the right hand end of the machine as shown in Fig. 1.

The housing structure, or framework of the sewing machine illustrated in the drawing, comprises a rectangular supporting bottom plate A, and a sewing machine framework proper which is screw connected to the bottom plate andincludes a`rectangular base or' bed portion A', a standard A,y and a horizontal cylinder arm comprising a portion A5 and A6. The 4portion A5 is an integral tubular extension of the base portion A' and A6 is a tubular part detachably secured tothe front end of the part A5 and forming an extension of the latter.

The machine comprises a driving motor B, mounted in the base portion A and having a pulley B on its shaft which is operatively connected by a belt C to a driving pulley D mounted on the adjacent; end of the needle bar shaft E, which may be journalled in the arm A3 in any usualor suitable manner. In the preferred construction shown, the rear end E ofthe needle bar shaft E is threaded, and supports a nut member F, lwhich may be rotated about the shaft end E to thereby clamp the hub portion of the pulley D between the head of the nut member E and the radially extending ange of a part E2 carried by and secured to the shaft E and comprising a vtubular hub portion E3 forming an elongated bearing for the pulley D. When the nut F is backed o", as shown in Fig. 2, the pulley E may be displaced axially of the shaft E, from its normal position, to thereby move the inner, belt groove portion of the pulley out of its normal position within the arm A3 so as to permit the belt C to be removed from and replaced on said pulley.

As shown, a washer member F is interposed between the nut F and the hub of the pulley D, said washer member having integral arm extensions F2 received in longitudinal slots formed for the purpose in the tubularportion E3 of the parl; E2. The member VF with its extensions F and the part E2 with the slots in its tubular portion E3, collectively form a split or extensible bearing Y for the pulley D, which provides a satisfactory support for the latter when in, and when displaced from, the position in which it is normally clamped by the nut F.

At its head end, the machine comprises means including a crank disc E", carried by the shaft for actuating a needle bar G, mounted in the head A4 in any usual or suitable manner for verticalland in our said prior application, we di-sclose and claim novel actuating means for lifting said presser bar during each` upstroke of the needle bar when the machine is in condition for darning, but as said actuating means form no part of the invention claimed herein, said means need not be illustrated or described. The sewing machine also includes tensionY and thread take-up provisions which may be of conventional type and hence do not require description herein.

The sewing machine mechanism shown, is of the rotary hook type, and comprises a hook shaft I, which is suitably journalled in the frame part A' and its cylinder arm extension A5, and which carries a loop taker or hook element i adjacent the front of the machine. The hook shaft I is rotated by the needle bar shaft E through a vertical shaft I journalled in the standard A2 and having its upper end connected to the shaft E by bevel gears 122 and having its lower end connected to the hook shaft I through bevel gears throat or needle plate part KA, ofl conventional flat form and supported by the cylinder arm part A6. The work feeding -means also comprises mechanism within the hollow cylindrical arm of the sewing machine for giving the feed dog its feeding movements. Said mechanism is fully disclosed in our said prior application, and need not be further referred to herein. 4

As shown in Fig. 3, the shaft of the motor B is parallel to the needle bar shaft lill and hook shaft I, but is laterally displaced from the latter. To accommodate this displacement without requiring the standard A2 to have an unconventional and ing connection between the motor and the needle undesirable form, an idler pulley N, normally` D is within and closely encircled by a cylindrical portion A1o of the framework. An opening formed in the standard A2 and base member A', at the right hand end of the machine, as seen. in Fig. 1, is normally closed by a removable cover plate or member A11, shown in outline in Fig. 6. The removal of the cover member A11 gives access to the portion ofthe belt and other mechanism within the hollow standard. As will be apparent, the belt may be slackened preparatory to its removal, and tightened up in the course of its replacement, by moving the belt into and out of engagement with the accessible idler pulley N while the belt is in engagement with the less accessible-pulleys B and D.

As shown the sewing machine includes a re-- movable work bed member P, in the form of a metal box minus its bottom wall and open at its with an opening P' in its 'top wall to receive the throat plate member KA and with an adjacent'l opening P2 partly in the top wall and partly in.

the closed end of the member P which is normally closed by a hinged cover member P3, which.

when moved into its open position, permits access to the bobbin case extending intol the loop taker, for insertion and removal of'bobbins. As shown, the base plate A is formed with an uprising marginal flange AA in telescopic engagement with the lower portion vof the beni. plate part P, whereby the latten is anchored in posi-` tion. With the part P in place, the machine as a whole, has'the general appearance and operative capacity of an ordinary :dat bed sewing machine. With the bed member P removed, the work support is of the cylinder arm form heretofore used in'darning stockings and other work.1 As shown in Fig. 4, the tubular cylinder arm may vadvantageously be generally elliptical in cross section but with its top portion attened to provide a flat seat for the engaging top wall portion of the member P.

'As shown, a bobbin Winder wheel Q, carried by an arm Q' pivotally connected to the standard A2, is adapted to be vturned from its idle position, shown in Fig. 3 intothe position in which the wheel Q extends through a slotformed for the purpose in the standard A2, and frictionally engages the pulley D, which, during the bobbin winding operation is normally free to turn on the needle shaft E.

As previously stated, the machine may be used interchangeably in plain sewing and darning operations, either with the flat bed part P in place, or removed, so that the work may be supl ported on the cylinder arm. Our improved drivshaft is relatively simple,'.and with it the belt removal and replacement operations are simple and of "a character to be readily performed by the ordinary..l housewife. The sewing machine shown is o'f the portable type, but our improve# ments disclosed and claimed herein are adapted for use in sewing machines of other types.

While in accordance with the provisions of the statutes, we have illustrated and described the best form of embodiment of the invention now known to us, it will be apparent to those skilled in the art that changesmay be made in the form of the apparatus disclosed vwithout departing from the spirit of the invention as set forth in the appended claims and that in some cases certain features of our invention may be used to advantage vwithout a corresponding use of other features.

Having now describedv our invention, what we claim as new and` desirsto secure by Letters Patent, is: Y

1. A motor driven -sewing machine comprising a framework including a base portion, a hollow standard, and an arm connected to the upper tween said ymotor and shaft, comprising a pulley member mounted on the rear end portion of said shaft and having a pulley groove at its front side,

of said recess, and a belt extending through said standard and normally having its upper portion received in said pulley groove but being movable into and out of said groove when the latter is out of said recess.

2. A sewing machine as specied in claim 1, in which said standard is formed with an opening in its rear side permitting access to the adjacent portion of the belt, and a detachable cover plate normally closes said opening,

3. A sewingmachine as specii'led in claim 1, in which a split bearing is interposed between said pulley and shaft and comprises portions extending longitudinally of said shaft and overlapping one another and being movable relative to one another in the longitudinal direction of the shaft to accommodate the longitudinal movement of the pulley.

4. A motordriven sewing machine comprising a framework including a base portion, a hollow standard and an arm connected to the upper end of the standard, a needle shaft having a body portion within and extending longitudinally of said arm and a rear end portion extending over the standard, a pulley member mounted on the rear end portion of said shaft, a driving motor mounted in said base portion having a driving pulley revolving about an axis parallel to the needle shaft and displaced to one side of said standard and a belt extending through said standard and about said pulley member and driving pulley, and -an idler pulley mounted in said standard and engaging a portion of said belt and deiiecting it .toward the center of the standard, whereby said belt may be slackened preparatory to its removal and tightened up in the course of its replacement, by moving the belt 

